Today, one of the major areas of concern for insurance companies is to calculate insurance premium based on driving behavior of a driver driving a vehicle. It has been observed that the insurance premium may be calculated using a telematics application such as usage-based insurance (UBI) or Pay as You Drive (PAYD). The telematics application may facilitate measuring and analyzing the driving behavior for calculating the insurance premium. In order to analyze the driving behavior, the insurance companies may define a few specific driving signatures associated with one or more risk events for which the insurance premium may be calculated. Examples of the one or more events may include hard brake, harsh acceleration, harsh deceleration, hard cornering. The driving signatures plays a vital role in determining the insurance premium based on the one or more risk events for a specific driver and thus the principal idea behind using the UBI or the PAYD application is to measure acceleration, that is, a quick or sudden change of the speed of the vehicle for detecting at least one of the one or more risk events. Therefore, it is evident that a continuous monitoring and capturing of the speed of the vehicle is desired.
In conventional methods, speed of the vehicle may be measured using on board devices (OBDs) associated with the vehicle. However, the installation or deployment of the OBDs for measuring the speed requires huge investment cost. With the deep penetration of smart phones and mobile applications worldwide, the insurance companies are optimistic that smart phones may be replaced with the OBD 2 device for measuring the speed. For such cases, a driver own smart phone may be used for the UBI application. In general, the smart phones include a GPS and an inertial navigation system (INS) comprising three axis accelerometer and gyroscope. The three axis accelerometer measures the speed of the vehicle but may include an error while measuring the speed and therefore does not indicate correct speed of the vehicle. This is because, when the orientation of the three axis accelerometer changes, due to change in the orientation of the smart phone, it becomes intricate to make judicious assessment in variation of the speed, and hence there is an error in the speed measured by the three axis accelerometer.
Though the GPS, on the other hand, does not depend on the orientation of the smart phone and may be used worldwide, any place, any time but the GPS based navigational system may not be accurate since it follows probabilistic approach towards measuring both the position co-ordinates of the vehicle as along with the speed. Further, GPS receivers, while doing such measurements, may indicate the error in measuring the speed, using the parameter called horizontal accuracy (HA) or Dilution of Precision (DOP). In one aspect, the HA indicates that the signal to noise ratio of the GPS signal received is low and therefore there exist the error in the measurement. Further, it has been observed that the GPS measurements require at least four visible satellites. In dense urban areas, sometimes, the visibility is lost, resulting in either no measurement or completely spurious measurement.
The GPS speed may provide an accurate measure of the speed when the vehicle is moving at a constant speed as the GPS based speed is internally filtered to determine the correct speed. However, in case of sharp acceleration or sharp deceleration, due to sudden application of brake, the GPS may not provide the accurate measure of the speed since the GPS is not capable to consider sudden changes in the speed (i.e. sharp acceleration or sharp deceleration). Thus, in view of the above, it is evident that the speed measured from the GPS includes multitude of potential errors that is to be eliminated in order to determine the correct speed of the vehicle for detecting the one or more risk events.